Broad, long-term objective: to improve quality of life (QOL) of patients with end-stage cancer. Specifically, we propose to investigate the use of the herbal medicine, Viscum album L. (mistletoe), as a supplemental therapy to conventional treatment of Stage IV non-small cell lung carcinoma (NSCLC). CAM systems may bring additional benefits to patients already receiving standard medical care. Mistletoe is a promising candidate because extracts and isolates of this plant are already in wide use by cancer patients and because those small studies that have been reported suggest that it is both safe and efficacious in improving QOL. Hypothesis: supplemental treatment with Iscar Mali, an herbal medicine made from the total plant extract of mistletoe, improves immune function and quality of life among Stage IV NSCLC patients receiving conventional chemotherapy. Aims: 1) To determine whether supplemental treatment with Iscador Mali in patients with Stage l\7 NSCLC (l.a.) will increase markers of immune function (as determined by total lymphocyte count, eosinophil count, and lymphocyte subset analysis), AND (l.b.) is well-tolerated by these patients at doses that effectively enhance the immune system; 2) To gather preliminary data for future hypothesis testing on the correlation between immune parameters and six, independent quality of life (QOL) measurements in Stage IV NSCLC patients treated as described in Aim 1. Significance: This Phase 11 clinical trial may i) aid clinicians j and patients by establishing immune parameters as markers of biological response to Iscar therapy; ii) help refine dosing guidelines; iii) suggest QOL improvement, justifying a larger, randomized clinical trial; iv) show that improvements in immune parameters correlate with increases in QOL and justify further evaluation of the immunological mechanisms of Iscar Therapy; or v) serve to caution clinicians and patients away from lscar therapy and towards safer therapies, should negative therapeutic effects be demonstrated.